Koschei
by MadDragon13
Summary: The world's ending, and nobody on Earth can stop it. Sherlock tries to savor his last moments with John. ...The operative phrase being "on Earth," if you haven't already figured that out. Johnlock, 10/Master.


**A/N: Sooo yeah. I have no idea where this is in DW canon, I really like blond Master and Ten but I know the only time he was blond is End of Time, which of course presents all kinds of problems. Remember to review! :D**

* * *

Sherlock awakes with a snap at the end of the world.

His infallible mental clock says _fifteen minutes. _Then the land will burn, the seas boil and evaporate and the Earth take its final bow as solar eruptions consume the planet in a fiery display. It sounds beautiful, in a terrible sort of way. He rather wishes he could see it.

It's been agreed upon by the titans of the world – government leaders, top scientists, finally united in the face of inescapable incineration – to refrain from informing the general populace. Nothing would be improved by the inevitable rampant panic and desperation, and any attempts to "set one's affairs in order" would be in vain as said affairs soon would cease to exist.

Sherlock curls further into his blogger's body, nuzzling his face into John's hair and inhaling deeply the scent of tea and shampoo. If this were the last thing he smelled, he would happily consider his life a success. This isn't a bad way to go, he thinks, snuggled protectively with the man he loves, arms wrapped firmly around his waist. He presses a soft kiss to the top of John's head.

"Sher?" John mumbles sleepily, having been woken by Sherlock's affection. He slowly rolls over, facing the detective, and yawns. "'Time's it?"

Sherlock smiles sadly. "Doesn't matter today." He lifts a hand and tenderly strokes the side of John's face, running his fingers down John's jawline before moving them back to rest at the back of his neck. John returns the gesture by sliding his hand through Sherlock's own messy curls, twirling them around his fingers. Sherlock closes his eyes and sighs contentedly as tingles race up and down his spine – he always did have a very sensitive scalp – before his eyes snap open with new intensity and he takes John's face in both hands.

"John. You know that I love you, right?"

The other man laughs softly – _ignorant, unsuspecting, beautiful__ – _and gives Sherlock a reassuring smile. "Of course I do. Love you too, Sher."

Sherlock leans forward and presses his lips to John's, who returns the kiss gladly. It's almost time for the apocalypse, and let this be the last thing he experiences, the last thing to remember before the instant of light and heat and then oblivion. He wants to die happy, and right now he is happy, enfolded around his perfect other half and kissing him like the world isn't endi –

_BANG_.

But it's not the _bang _of absoluteness as the Earth is snuffed out like a candle. It's not the _bang _of the sun's corona flaring across the solar system and incinerating everything in its path. It's not the _bang _at the end of the universe (quite as big as its earlier counterpart).

Rather, it is the _bang _of someone knocking on the door of 221b Baker Street, London, England, Earth, which has, apparently, _not_ been consumed in flames.

Sherlock blinks. By all rights, he should be dead by now. Not that he's complaining, necessarily, but – _what the hell happened?_

The banging continues. Whoever it is sounds very big, or very committed, or both. Sherlock reluctantly extricates himself from the tangle of limbs that is he and John and gets up to investigate. Maybe the person at the door will have some answers in regard to this situation.

The morning sun shines through the window as Sherlock pads barefoot towards the door. It's just after dawn, early enough that London is still stifled in a lovely blanket of silence and tranquility, nobody awake except for John, Sherlock, and whoever it is on the doorstep of 221b. The detective frowns as the quiet is disrupted by yet another _bang. _He wishes John were with 's not right about this mystery caller.

It's not a client. The knock is too loud, too brash. Or desperate? But if it were truly desperate, it would be a rapid-fire _knockknockknockknock, _not this occasional thumping. It's not Mycroft (taps gently with knocker after straightening it), Lestrade (knocks solidly three times before waiting forty seconds and knocking again), Molly (timidly presses doorbell, usually once depending on the urgency of the situation), or Mrs. Hudson (two quick raps followed by a "yoohoo!"). It's not the police, too arrhythmic, not a member of the homeless network, too strong. In fact, Sherlock can deduce next to nothing about the person on the other side of the door, aside from the fact that they are very intent on coming in.

Scowling with a mixture of frustration, puzzlement, and fear, Sherlock grasps the door handle and flings it open.

"Hello," says the man leaning heavily on the doorframe, covered in blood. Sherlock stares.

The man has short, white-blond hair with piercing blue eyes. He is wearing a torn, scarlet-stained black hoodie with a red t-shirt underneath and mud-covered trainers. His face shines with sweat and blood over of a thick layer of grime and he's covered with small cuts and injuries. His hand clasps one shoulder, streams of blood flowing from an unseen wound. An air of cockiness and intelligence surrounds him, despite his wounded state. And Sherlock _can__'__t deduce a thing about him._

"D'you mind if I come in?" asks the stranger casually. "Only I think I'm bleeding to death. Possibly. I don't really know."

Sherlock blinks with confusion.

"JOHN!"

Within five minutes, the man is seated uncomfortably on the couch, having his shoulder fussed over by John and refusing to tell the two anything about how he received the wound or why he came to their flat. A scowling Sherlock hands him a wet cloth to clean his face with – _he__'__s getting bloodstains on my Mind Palace couch __– _before retreating to his chair to sulk.

"Sherlock – " the doctor begins exasperatedly, looking up from the man's shoulder. His eyes catch the mystery man's and he pauses.

"I know you," says John slowly. "You're that bloke Harold Saxon! Ran for prime minister a few years back!" That explains why Sherlock hadn't recognized the man. Politics were even more boring than the solar system, if that were possible.

Saxon winces as if the words cause him physical pain. "I've committed too many atrocities under that name. Call me Koschei, please."

"Koschei?" Sherlock lifts his head and turns over. "Little-known Slavic fairytale antagonist, appears in _The Death of Koschei the Deathless, _described as an immortal being who kidnaps the hero's wife. An alibi, obviously, but obscure enough that it could pass for an actual name. Interesting choice, I must say, you aren't Slavic so how did you come across this story? Read a lot as a child? Your cover's blown, by the way, may as well tell us who sent you here. Not Mycroft, you're too shabbily dressed for him, Moriarty? Some other criminal I've annoyed?"

"No," replies Koschei peevishly. "That's my _name_."

Sherlock opens his mouth and closes it, mind whirring. "Is that so? In that case, what's your surname?"

Koschei glares.

"Sherlock," says John suddenly. "Come and take a look at this."

"What've you found?" inquires Koschei curiously as Sherlock rolls onto the floor and scoots over to John's side, perching his chin on the doctor's shoulder. "I'd rather like to know, it's me you're poking at. Oh. Yes, it's supposed to look like that."

John is staring, brow furrowed, at the large expanse of bloody gauze he's been using to patch up Koschei's wound. Only it doesn't appear bloody. It looks as if someone's splattered it with hot sauce – a deep, burnt orange color.

Sherlock swipes his fingers across the gauze and brings them up to his nose. He sniffs, makes a face, and very carefully places a finger on his tongue.

"Sherlock, what – " John exclaims with shock.

Koschei cuts him off. "Mostly sour, hints of salt and sweetness, correct? I know what my own blood tastes like, thank you."

"What are you?" murmurs Sherlock. "You're impossible. You can't be human."

"Brilliant deduction."

John takes a step back. "Are you really saying that you're – what? An alien?"

Koschei rolls his eyes. _"__No, _I'm from _Cornwall, _I just fell in a vat of _toxic waste _as a child. _Yes, I__'__m an alien!__"_

"I – I can't treat you! I don't know anything about alien biology!"

"Listen." Koschei drops the sarcasm and looks at John earnestly. "You're doing great. I'm close enough that there shouldn't be much difference. Thanks for this, by the way."

"Of course," replies John, dazedly.

Sherlock scowls harder and wraps his arms clingily around his blogger.

"_Really_, Sher – anyway, have you been feeling any wooziness, or lightheadedness?"

"Yep. Managing to suppress it, though."

"You're going to need a transfusion." John sighs, looking defeated. "I have no idea how this is going to happen."

Koschei says something that sounds like it would offend just about anyone, had they been on the planet from which it originated. "Phone. Need a phone."

John blinks. "You mean you can just – _call _someone, another of your species? How many of you are there, anyway?"

Koschei sighs, looking sad for a brief second. "One. He thinks."

"Oh. I'm – sorry?"

"I'm still dying._ Phone_. Thanks."

Koschei takes John's proffered mobile, deftly dialing with one hand and pressing it to his ear. "Doctor? Hey, yeah. It's Koschei."

Muffled noise from the other end of the line. Koschei winces. "Do _not _call me that. That is _not _my name."

Pause. "Yes, I'm sane! The drums are gone! Long story, okay!"

The person on the other end seems to be having some sort of panic. Koschei makes small shushing sounds. "Listen. I need your help. I've been shot by a Phasrean and I'm bleeding all over Doctor Watson's couch. Incidentally, it's too early in their timeline for them to know about us. So about early June 2014?" He raises his eyebrows questioningly at John, who nods numbly.

"Yeah, early June 2014. How old are you? Just wondering. So…tenth? Well, technically…" He snickers. "Sorry! Our secret. And, you know, there's also the whole _time war, _but whatever." Another pause. "Yes, I am stalling so you don't question the integrity of this message…Thetaaa. Happy? I'm the only one who calls you that little nickname. Ever."

Evidently this doesn't pacify the mystery person on the other line. Koschei scowls and rolls his eyes at the ceiling. "Something I know about you that nobody else does. I could go so many ways with this." Pause. "But I'm not gonna because there's people looking confused. Including Sherlock Holmes. You confused Sherlock Holmes, did you know that? Congratulations. …No, I'm not drunk; I'm dying of blood loss, weren't you listening? No, I don't know the status of my regen cycle. It's the thing I'm least sure about in the universe at the moment. I literally have no idea if I'm going to live for millennia or just spontaneously combust at some point."

Silence as Koschei glares at the person on the other line. "I'm about two-thirds blacked out right now and you want me to tell you a story. Yes, to prove my identity, I know! Fine. Here we go." He takes a deep breath.

"So we're about 120 years old and we've snuck out of class, right? 'Cause it's boring, more so than usual. It's nice out, so we decide to take a walk in the forest. And you're nattering on about something you've invented, I think it was a sonic something or other." His speech slows gradually and he begins slurring his words. "An' I'm kinda really nervous so I'm not saying anything. Now norm'ly, I'd be rollin' my eyes an' snarking, so you go 'What's wrong, Kos? You're so quiet.' An' then that's the last straw b'coz your eyebrows went all together an' it was _adorable _so I just sorta slam you against the nearest tree an' start snoggin' you. An' I can tell issyour firs' time 'coz you're so clumsy an' it's adorable an' the firs' thing ya do after we pull away is walk into a bloody tree branch an' I'm passin' out now bye."

John lunges forward and catches the mobile as it falls out of Koschei's now limp hand. "Sherlock!" he hisses, tossing the phone to the detective, who catches it with a slightly dumbfounded look on his face. John quickly checks Koschei's vitals and breathes a sigh of relief. "Still alive, thank goodness. Love, would you mind…"

Sherlock nods and brings the phone to his ear with some trepidation. "Sherlock Holmes."

"Is he alright? Is – is Koschei okay?!" The panicked voice is almost drowned out by deafening background noise of screeching machinery and explosions. "Is he still alive – is he _glowing _at all, sort of a glimmery gold color?"

"No. John says he's just unconscious. Did you say – _glowing?__"_

"Ohhh, it's a long story." The man breathes a loud sigh as the cacophony subsides. "Oh _Koschei, _you've got so much explaining to do, you utter idiot…" He starts giggling exhaustedly. "Anyway, I'm the Doctor. I should be there in…about ten minutes, if all goes well. It probably will, it's too important not to…" There's a small click and the line goes dead.

Sherlock looks up. "Ten minutes."

John sighs with relief and collapses into his chair. "Thank God. This is just…this is the strangest day ever. I mean, he's an _alien, _for God's sakes, and for some reason he decided to come here…"

Abruptly, Sherlock crosses the room and clambers into John's lap, curling up against him and burying his face in the crook of John's neck. He holds John tightly and breathes long, calming breaths.

"Sherlock…what's wrong?" John's voice – _oh, John __– _soft, caring, concerned – is just the thing to push Sherlock over the edge. He swallows heavily. Tears drip slowly onto John's shoulder.

"What's going on?"

"I don't... I don't know. Okay? I've said it, I admit it, I don't know what's happening, I don't know who he is, I don't know about the Doctor, I'm so confused, I don't know when we're going to die, or if, I don't know if this moment is our last, I've never been so scared, I love you, John, I don't know what's going on, I don't know what I'm feeling, I don't know what to feel, my emotions are running haywire, I'm babbling, I can't stop, I don't know why, I don't know, I don't know anything!" Sherlock's voice goes up shrilly at the end. His fingers are clenched, trembling, in the fabric of John's jumper.

"Sherlock, shhh. Slow down. It's okay." John, though bewildered by this sudden outburst, does his best. He holds his surprisingly fragile genius, cupping the back of his neck and kissing his forehead comfortingly.

"It's _not! _It's _not okay, _John, it's not! You don't understand it, you can't, but John, John I don't know..." Sherlock curls further into John's chest and gives a whimpering sob.

"I've got you, Sherlock. Try to calm down. I'm right here. Now, why don't you take a few deep breaths and tell me what's going on in your head?"

"Th-the…" He inhales shakily, struggling not to become overwhelmed with the confusion and panic and dread warring inside his skull, threatening to escape. "Th-the world was s-supposed to end t-today."

John's hands stop their slow stroking up and down his back. "What?"

"The sun. It was g-going to explode. At s-six twenty-s-seven today, and it _d-didn__'__t. _And I don't know why, s-something's wrong, and I don't know when or if it will, and I'm _scared, _John, I'm so _scared!__"_His voice cracks.

"Wait." John pries Sherlock's head up from his shoulder. "You – _knew _about this? Why didn't you tell me?"

"C-couldn't have done anything…didn't want to w-worry you."

" – _Oh. _So when you were being all cuddly this morning…"

"Thought it would be a good way to die."

And John _understands. _Sherlock doesn't know why he ever thought he wouldn't. This is _John, _after all. The one person in all the world who fully knows, the one person he's claimed as _his. _There's no anger, no "We were all going to die?! Just like _that?!__"__. _Instead, John kisses the top of his head, like he's a small child who's woken up from a nightmare and needs the comfort of a loving parent. "That must have been hard. Knowing that, and not being able to tell."

Sherlock nods mutely, his curls rasping over John's face.

"And…for what it's worth…I think that would have been a nice way to die, too."

"I don't want the world to end," Sherlock says muffledly.

"Neither do I."

"I don't know if it will."

"Neither do I."

"I'm sorry. I'm sorry I didn't tell you."

"I love you."

"I love you too. So much."

John rests his nose in Sherlock's curls as his breathing slows to normal. It's so peaceful. Koschei is sleeping, everything is still in the flat. He can hear Mrs. Hudson waking up downstairs. It's hard to reconcile this picture with the apocalypse.

John closes his eyes. Maybe the end of the world will come, maybe it won't. But he's strangely happy. Sherlock appears to have gone to sleep. He feels as if he should wait for the Doctor before attempting to join him.

Suddenly, the door slams open. Sherlock falls gracelessly to the floor. The man stands silhouetted in the doorway for a fraction of a second before leaping over to Koschei, coat billowing magnificently. It's a strangely familiar maneuver to John, who helps Sherlock up before kissing him briefly and tapping the man's shoulder. "You're the Doctor. Right?"

"Yep, that's me," says the man distractedly. He kneels beside Koschei, checking his pulse, gingerly examining the wound. "Oh, Kos,what have you done..." The Doctor touches Koschei's face fondly before clearing his throat and turning around. "Right, I've got blood, he doesn't, this should be pretty straightforward, wouldn't you say? I'll need a couple needles, empty syringes, plastic tubing would be nice. You're a doctor, aren't you?"

"Ah, right," says John, and gives Sherlock's hand a quick squeeze before shuffling off to find some.

Sherlock watches him go, then turns to the Doctor. "What's happening."

"I'm not completely sure, myself. He's the one with a lot of the answers -" here the Doctor jabs a thumb towards Koschei's sleeping form - "and he's obviously...unavailable for comment. But the sun is safe, I can tell you that. Well, for the next five billion years or so. Give or take."

Sherlock says nothing. He can't deduce this one either. The Doctor stares unabashedly back.

"Hey, I've go the...uh..." says John articulately, holding out the necessary supplies.

The Doctor breaks eye contact first and leaps up to retrieve John's slightly dangerous bundle. He unwraps the plastic tubing from around the syringes, nodding gratefully to John, and places the nonlethal end of one syringe in his mouth while twisting the tube into the needle's chamber. He depresses the plunger and somehow locates tape on the coffee table without glancing away, and tapes the plunger in place. He then removes the other needle from his mouth and repeats the process without the tape.

"Almost ready. These are clean, right? 'Course they are. Right?"

"Ah, yeah," John replies, distracted somewhat by the fact that Sherlock has climbed back onto his lap and is playing with the hair at the base of his neck. The Doctor seems unfazed by such domesticity. He's concentrating on the makeshift transfusion cable, zapping it with a small blue-glowing device he's pulled out of his pocket. "Alright, she's ready to go."

The transfusion goes smoothly, the sight of Tabasco blood flowing thickly from one vein to the next oddly transfixing to Sherlock. Despite his outward charisma, the Doctor is tense and white, watching Koschei's face for any sign of life.

"He won't wake up yet," says John from under Sherlock. "That much blood loss, his brain doesn't have enough oxygen to function."

_"Well," _says the Doctor. He glances at his wrist and the needle protruding from it, then leans over to feel Koschei's forehead. He plucks out the tube quickly and efficiently, tilting the syringes up to avoid staining the carpet, and hands them to John. "Thanks. Means a lot. Anytime you need anything, call me, or talk to Torchwood. They know what they're doing. Here..." He produces a pen and scribbles down two numbers. "I'll tell them about you. If you don't mind, I'll just stick around until he wakes up...?"

"Oh, no, fine, stay as long as you want!" replies John. Sherlock grunts.

"Right." The Doctor perches on the arm of the sofa next to Koschei's head and looks out of place. "How tightly have you bandaged his shoulder? Only he's got two hearts, so it'll take more pressure to stop the bleeding."

John gapes. Sherlock can see wheels labeled _medical miracle _turning in his head. "How -"

"Looks like you've done it properly." The Doctor prods at the bandage with the end of his glowing stick-thing. "Ah, bigger on the inside, it's a long story." Restless, the lanky man shifts down to Koschei's level, pressing their foreheads together and closing his eyes.

"Well, this is awkward," Koschei murmurs suddenly.

The Doctor springs backwards, eyes wide. Koschei smirks triumphantly. "Hey, Theta. Long time no see."

"You're - but - you're - you're _sane!"_ splutters the Doctor, running his hands through his hair and gazing down at the other man. "I was in your head, and Kos - they're _gone!"_

Koschei's grin widens and he swings his feet off the couch, moving easily into a sitting position. "Actually, Theta dear, I've _kind _of noticed that myself."

"But - but _how?! _Oh, Kos, this is _brilliant!" _The Doctor's grin is encompassing his whole face. "How long have you - _what happened?!"_

"I can't tell you right now. Time streams, you know how it is, don't want to create a fixed point." Koschei ducks his head shyly, looking at the ground. "That - thing you said. A while ago. That thing about the...er, forgiveness? Does...does that still - Only my spaceship crashed, and I really don't know what to do next." He gives an embarrassed chuckle.

For a second, the Doctor is speechless.

Then he leans forward, putting a hand on Koschei's knee. "Yeah, of course." He speaks softly, as if trying not to spook a wild animal. "Course it does, Kos. The TARDIS kept your room."

"Oh," Koschei whispers.

_Spaceship. _John knows he shouldn't be surprised. Sherlock watches, brow furrowed, arms still around John's neck.

"What were you doing on Earth in the first place?" The Doctor breaks the silence after a heavy pause.

"Phasreans. Trying to make a quick buck blowing up this system's sun and harvesting the energy. You're not the only one capable of saving this planet's miserable behind." He smirks again, somewhat bitterly. "Could have used Torchwood's help, but I think at this point in time they'd much rather shoot me on sight. Justified, of course. Where were you?"

"Tunnekind! Haven't tangled with those things since Gallifrey! You remember?"

"Oh, that scavenger species, they can go years without sustenance and survive the vacuum indefinitely? Nasty buggers, aren't they? Remember when we swiped a practice TARDIS to go exploring and one got stuck in it?"

The Doctor laughs delightedly. "They suspended us from flight class for two months! Anyway, this bunch got it in their heads to shoot down the TARDIS -"

"Your TARDIS, that you stole," Koschei clarifies.

"My TARDIS, that I stole. I was in the middle of crashing when I got your call. Which reminds me, her automatic repairs are probably done, so we can leave whenever you're ready."

"Oh. Okay." Koschei tries to stand, stumbling a bit, but recovering quickly. The Doctor pops up, beaming, unable to look away from the blond man's face.

Koschei clears his throat awkwardly. "I...er, thank you, Doctor Watson, and I suppose, goodbye. I have a feeling we'll meet again." He reaches out to shake John's hand, but reconsiders at the sight of Sherlock's face.

"Think we'd better get out of their flat," the Doctor murmurs. "Let them have some time alone, Kos, what do you say?"

"Yes. Let's go. Oh, and Doctor?"

"Mm?"

"Thank you." Koschei puts a hand on the back of the Doctor's neck, pulling him down and kissing him gently on the lips.

The Doctor's eyes fly open, then slide shut as he leans into the kiss. His hands rest on Koschei's lower back, tightening slightly as he holds the shorter man to him. Koschei's arms move to wrap around the Doctor, pressing him close, deepening the kiss. The Doctor smiles, and a single tear escapes down his cheek.

"Missed you, Kos," he whispers.

"Missed you too. Now, do you want to continue this later? In the privacy of your box, perhaps?"

"Right. Allons-y?"

After a short silence, Koschei bursts out laughing. "Oh my _God, _Theta! Not another bloody catchphrase!?"

"What? What's wrong with catchphrases?" the Doctor protests as Koschei drags him to the door. "They're - they're _brilliant! _I don't know what you have against them - Koschei, wait - " He breaks away long enough to shout "Goodbye, Holmes-Watsons! Tell Mycroft to stay away from those diet pills - " before the door slams shut behind them.

The flat rings with sudden silence. Then:

_"What _did he call us?" asks John.


End file.
